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A253400
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Number of (n+1)X(1+1) 0..2 arrays with every 2X2 subblock diagonal maximum plus antidiagonal minimum unequal to its neighbors horizontally, vertically and ne+sw antidiagonally
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1
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81, 480, 2890, 17560, 106540, 646240, 3920448, 23781448, 144267352, 875147104, 5308894208, 32204831776, 195362700680, 1185113825256, 7189187420440, 43611271279904, 264556337839152, 1604860554179552, 9735463002163768
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 2*a(n-1) +24*a(n-2) +7*a(n-3) -15*a(n-4) -84*a(n-6) -139*a(n-7) -28*a(n-8) -14*a(n-9) -24*a(n-10) for n>11
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EXAMPLE
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Some solutions for n=4
..2..0....1..0....0..1....0..0....0..2....1..2....0..0....0..0....1..2....2..2
..0..1....2..0....0..0....1..2....0..0....0..1....2..1....2..1....2..2....2..2
..2..0....0..1....2..2....0..1....2..1....2..1....0..1....1..1....1..0....0..0
..1..2....2..0....2..0....2..1....1..0....1..2....2..0....1..1....2..0....2..1
..2..1....2..2....2..0....2..2....0..2....1..1....2..0....2..2....0..2....2..1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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